Mr. Bollinger, who will turn 76 this month, led Columbia to a 17-acre expansion north of 125th Street in Harlem, an area known as Manhattanville. It is now the site of towering new glass buildings housing centers for science, the arts and business.
In the announcement of Mr. Bollinger’s pending departure, Columbia said it had worked with communities surrounding the new campus “to support priorities like housing and education and to build alliances that are creating vital bonds with our neighbors and defining a new era of collaboration and progress.”
However, those sentiments hide a more contentious reality. At first, the expansion threatened to become a new chapter in Columbia’s long history of friction with the surrounding Harlem neighborhood in a town-and-gown conflict between the privileged world of academia and the often forgotten world of the poorer neighborhood around it.
A spokeswoman for Columbia, Victoria Benitez, said the university had tried to address community concerns by helping businesses to relocate or preserving them, stepping up resources for local youth and building affordable housing.
Keith Wright, a state assemblyman from Harlem for several decades, was intimately involved in negotiating with Columbia over the expansion, which Harlem residents feared would displace them and local businesses. Mr. Wright, now a consultant, recalled that negotiators had spent almost 24 hours locked in a room before they came out with an agreement over the project.
The goal of community leaders, Mr. Wright said on Thursday, was “to create a pipeline so Columbia University can be accessible to folks down in the valley.”
“I think we got a lot of community giveback,” he added.
Mr. Bollinger, a First Amendment scholar, attracted attention in 2007 by inviting the president of Iran, Mahmoud Ahmadinejad, to speak at Columbia and then attacking Mr. Ahmadinejad’s record as he sat nearby. At least one professor at Columbia accused Mr. Bollinger of inappropriately dabbling in politics.